Modifying Behavior of Autonomous Vehicles Based on Sensor Blind Spots and Limitations

ABSTRACT

Models can be generated of a vehicle&#39;s view of its environment and used to maneuver the vehicle. This view need not include what objects or features the vehicle is actually seeing, but rather those areas that the vehicle is able to observe using its sensors if the sensors were completely un-occluded. For example, for each of a plurality of sensors of the object detection component, a computer may generate an individual 3D model of that sensor&#39;s field of view. Weather information is received and used to adjust one or more of the models. After this adjusting, the models may be aggregated into a comprehensive 3D model. The comprehensive model may be combined with detailed map information indicating the probability of detecting objects at different locations. The model of the vehicle&#39;s environment may be computed based on the combined comprehensive 3D model and detailed map information.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.17/512,770, filed Oct. 28, 2021, which is a continuation of U.S.application Ser. No. 16/773,606, filed Jan. 27, 2020, which is acontinuation of U.S. application Ser. No. 15/718,794, filed Sep. 28,2017, which is a continuation of U.S. application Ser. No. 15/137,120,filed on Apr. 25, 2016, which is a continuation of U.S. application Ser.No. 13/749,793, filed on Jan. 25, 2013. The foregoing applications areincorporated herein by reference.

BACKGROUND

Autonomous vehicles use various computing systems to aid in thetransport of passengers from one location to another. Some autonomousvehicles may require some initial input or continuous input from anoperator, such as a pilot, driver, or passenger. Other systems, forexample autopilot systems, may be used only when the system has beenengaged, which permits the operator to switch from a manual mode (wherethe operator exercises a high degree of control over the movement of thevehicle) to an autonomous mode (where the vehicle essentially drivesitself) to modes that lie somewhere in between.

Such vehicles are equipped with various types of sensors in order todetect objects in the surroundings. For example, autonomous vehicles mayinclude lasers, sonar, radar, cameras, and other devices which scan andrecord data from the vehicle's surroundings. These devices incombination (and in some cases alone) may be used to build 3D models ofthe objects detected in the vehicle's surrounding.

In addition to modeling and detecting objects in the vehicle'ssurroundings, autonomous vehicles need to reason about the parts of theworld that are not seen by these sensors (e.g., due to occlusions) todrive safely. Without taking into account the limitations of thesesensors, this may lead to dangerous maneuvers such as passing aroundblind corners, moving into spaces that are partially occluded by otherobjects, etc.

SUMMARY

One aspect of the disclosure provides a method. The method includesgenerating, for each given sensor of a plurality of sensors fordetecting objects in a vehicle's environment, a 3D model of the givensensor's field of view; receiving weather information including one ormore of reports, radar information, forecasts and real-time measurementsconcerning actual or expected weather conditions in the vehicle'senvironment; adjusting one or more characteristics of the plurality of3D models based on the received weather information to account for animpact of the actual or expected weather conditions on one or more ofthe plurality of sensors; after the adjusting, aggregating, by aprocessor, the plurality of 3D models to generate a comprehensive 3Dmodel; combining the comprehensive 3D model with detailed mapinformation; and using the combined comprehensive 3D model with detailedmap information to maneuver the vehicle.

In one example, the 3D model of each given sensor's field of view isbased on a pre-determined model of the given sensor's unobstructed fieldof view. In another example, the 3D model for each given sensor's fieldof view is based on the given sensor's location and orientation relativeto the vehicle. In another example, the weather information is receivedfrom a remote computer via a network. In another example, the weatherinformation is received from one of the plurality of sensors. In anotherexample, at least one model of the plurality of 3D models includesprobability data indicating a probability of detecting an object at agiven location of the at least one model, and this probability data isused when aggregating the plurality of 3D models to generate thecomprehensive 3D model. In another example, the detailed map informationincludes probability data indicating a probability of detecting anobject at a given location of the map, and this probability data is usedwhen combining the comprehensive 3D model with detailed map information.In another example, combining the comprehensive 3D model with detailedmap information results in a model of the vehicle's environmentannotated with information describing whether various portions of theenvironment are occupied, unoccupied, or unobserved.

Another aspect of the disclosure provides a system. The system includesa processor configured to generate, for each given sensor of a pluralityof sensors for detecting objects in a vehicle's environment, a 3D modelof the given sensor's field of view; receive weather informationincluding one or more of reports, radar information, forecasts andreal-time measurements concerning actual or expected weather conditionsin the vehicle's environment; adjust one or more characteristics of theplurality of 3D models based on the received weather information toaccount for an impact of the actual or expected weather conditions onone or more of the plurality of sensors; after the adjusting, aggregatethe plurality of 3D models to generate a comprehensive 3D model; combinethe comprehensive 3D model with detailed map information; and use thecombined comprehensive 3D model with detailed map information tomaneuver the vehicle.

In one example, the 3D model of each given sensor's field of view isbased on a pre-determined model of the given sensor's unobstructed fieldof view. In another example, the 3D model for each given sensor's fieldof view is based on the given sensor's location and orientation relativeto the vehicle. In another example, the weather information is receivedfrom a remote computer via a network. In another example, the weatherinformation is received from one of the plurality of sensors. In anotherexample, at least one model of the plurality of 3D models includesprobability data indicating a probability of detecting an object at agiven location of the at least one model, and this probability data isused when aggregating the plurality of 3D models to generate thecomprehensive 3D model. In another example, the detailed map informationincludes probability data indicating a probability of detecting anobject at a given location of the map, and this probability data is usedwhen combining the comprehensive 3D model with detailed map information.In another example, combining the comprehensive 3D model with detailedmap information results in a model of the vehicle's environmentannotated with information describing whether various portions of theenvironment are occupied, unoccupied, or unobserved.

A further aspect of the disclosure provides a tangible, non-transitorycomputer-readable storage medium on which computer readable instructionsof a program are stored. The instructions, when executed by a processor,cause the processor to perform a method. The method includes generating,for each given sensor of a plurality of sensors for detecting objects ina vehicle's environment, a 3D model of the given sensor's field of view;receiving weather information including one or more of reports, radarinformation, forecasts and real-time measurements concerning actual orexpected weather conditions in the vehicle's environment; adjusting oneor more characteristics of the plurality of 3D models based on thereceived weather information to account for an impact of the actual orexpected weather conditions on one or more of the plurality of sensors;after the adjusting, aggregating the plurality of 3D models to generatea comprehensive 3D model; combining the comprehensive 3D model withdetailed map information; and using the combined comprehensive 3D modelwith detailed map information to maneuver the vehicle.

In one example, the 3D model of each given sensor's field of view isbased on a pre-determined model of the given sensor's unobstructed fieldof view. In another example, at least one model of the plurality of 3Dmodels includes probability data indicating a probability of detectingan object at a given location of the at least one model, and thisprobability data is used when aggregating the plurality of 3D models togenerate the comprehensive 3D model. In another example, the detailedmap information includes probability data indicating a probability ofdetecting an object at a given location of the map, and this probabilitydata is used when combining the comprehensive 3D model with detailed mapinformation.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a functional diagram of a system in accordance with anexemplary embodiment.

FIG. 2 is an interior of an autonomous vehicle in accordance with anexemplary embodiment.

FIG. 3 is an exterior of an autonomous vehicle in accordance withaspects of the disclosure.

FIGS. 4A-D are diagrams of an autonomous vehicle in accordance withaspects of the disclosure.

FIG. 5 is an example of detailed map information in accordance withaspects of the disclosure.

FIG. 6 is another example of detailed map information in accordance withaspects of the disclosure.

FIG. 7A is a pictorial diagram of a system in accordance with aspects ofthe disclosure.

FIG. 7B is a functional diagram of a system in accordance with aspectsof the disclosure.

FIGS. 8A and 8B are examples of the components of a 3D model for asensor in accordance with aspects of the disclosure.

FIGS. 9A and 9B are other examples of the components of a 3D model for asensor in accordance with aspects of the disclosure.

FIG. 10 is an example of a comprehensive 3D model for a plurality ofsensors in accordance with aspects of the disclosure.

FIG. 11 is another example of a comprehensive 3D model for a pluralityof sensors in accordance with aspects of the disclosure.

FIG. 12 is an example of a comprehensive 3D model for a plurality ofsensors combined with detailed map information in accordance withaspects of the disclosure.

FIG. 13 is an example flow diagram in accordance with aspects of thedisclosure.

DETAILED DESCRIPTION

Aspects of the present disclosure relate generally to modeling avehicle's current view of its environment. This view need not includewhat objects or features the vehicle is actually seeing, but ratherthose areas that the vehicle is able to observe using its sensors if thesensors were completely un-occluded. For example, for each of aplurality of sensors of the object detection component, a computer mayan individual 3D model of that sensor's field of view. Weatherinformation is received and used to adjust one or more of the models.After this adjusting, the models may be aggregated into a comprehensive3D model. The comprehensive model may be combined with detailed mapinformation indicating the probability of detecting objects at differentlocations. A model of the vehicle's environment may be computed based onthe combined comprehensive 3D model and detailed map information and maybe used to maneuver the vehicle.

As shown in FIG. 1 , an autonomous driving system 100 in accordance withone aspect of the disclosure includes a vehicle 101 with variouscomponents. While certain aspects of the disclosure are particularlyuseful in connection with specific types of vehicles, the vehicle may beany type of vehicle including, but not limited to, cars, trucks,motorcycles, busses, boats, airplanes, helicopters, lawnmowers,recreational vehicles, amusement park vehicles, farm equipment,construction equipment, trams, golf carts, trains, and trolleys. Thevehicle may have one or more computers, such as computer 110 containinga processor 120, memory 130 and other components typically present ingeneral purpose computers.

The memory 130 stores information accessible by processor 120, includinginstructions 132 and data 134 that may be executed or otherwise used bythe processor 120. The memory 130 may be of any type capable of storinginformation accessible by the processor, including a computer-readablemedium, or other medium that stores data that may be read with the aidof an electronic device, such as a hard-drive, memory card, ROM, RAM,DVD or other optical disks, as well as other write-capable and read-onlymemories. Systems and methods may include different combinations of theforegoing, whereby different portions of the instructions and data arestored on different types of media.

The instructions 132 may be any set of instructions to be executeddirectly (such as machine code) or indirectly (such as scripts) by theprocessor. For example, the instructions may be stored as computer codeon the computer-readable medium. In that regard, the terms“instructions” and “programs” may be used interchangeably herein. Theinstructions may be stored in object code format for direct processingby the processor, or in any other computer language including scripts orcollections of independent source code modules that are interpreted ondemand or compiled in advance. Functions, methods and routines of theinstructions are explained in more detail below.

The data 134 may be retrieved, stored or modified by processor 120 inaccordance with the instructions 132. For instance, although the claimedsubject matter is not limited by any particular data structure, the datamay be stored in computer registers, in a relational database as a tablehaving a plurality of different fields and records, XML documents orflat files. The data may also be formatted in any computer-readableformat. By further way of example only, image data may be stored asbitmaps comprised of grids of pixels that are stored in accordance withformats that are compressed or uncompressed, lossless (e.g., BMP) orlossy (e.g., JPEG), and bitmap or vector-based (e.g., SVG), as well ascomputer instructions for drawing graphics. The data may comprise anyinformation sufficient to identify the relevant information, such asnumbers, descriptive text, proprietary codes, references to data storedin other areas of the same memory or different memories (including othernetwork locations) or information that is used by a function tocalculate the relevant data.

The processor 120 may be any conventional processor, such ascommercially available CPUs. Alternatively, the processor may be adedicated device such as an ASIC or other hardware-based processor.Although FIG. 1 functionally illustrates the processor, memory, andother elements of computer 110 as being within the same block, it willbe understood by those of ordinary skill in the art that the processor,computer, or memory may actually comprise multiple processors,computers, or memories that may or may not be stored within the samephysical housing. For example, memory may be a hard drive or otherstorage media located in a housing different from that of computer 110.Accordingly, references to a processor or computer will be understood toinclude references to a collection of processors or computers ormemories that may or may not operate in parallel. Rather than using asingle processor to perform the steps described herein, some of thecomponents, such as steering components and deceleration components, mayeach have their own processor that only performs calculations related tothe component's specific function.

In various aspects described herein, the processor may be located remotefrom the vehicle and communicate with the vehicle wirelessly. In otheraspects, some of the processes described herein are executed on aprocessor disposed within the vehicle and others by a remote processor,including taking the steps necessary to execute a single maneuver.

Computer 110 may all of the components normally used in connection witha computer such as a central processing unit (CPU), memory (e.g., RAMand internal hard drives) storing data 134 and instructions such as aweb browser, an electronic display 142 (e.g., a monitor having a screen,a small LCD touch-screen or any other electrical device that is operableto display information), user input 140 (e.g., a mouse, keyboard, touchscreen and/or microphone), as well as various sensors (e.g., a videocamera) for gathering explicit (e.g., a gesture) or implicit (e.g., “theperson is asleep”) information about the states and desires of a person.

In one example, computer 110 may be an autonomous driving computingsystem incorporated into vehicle 101. FIG. 2 depicts an exemplary designof the interior of an autonomous vehicle. The autonomous vehicle mayinclude all of the features of a non-autonomous vehicle, for example: asteering apparatus, such as steering wheel 210; a navigation displayapparatus, such as navigation display 215; and a gear selectorapparatus, such as gear shifter 220. The vehicle may also have varioususer input devices, such as gear shifter 220, touch screen 217, orbutton inputs 219, for activating or deactivating one or more autonomousdriving modes and for enabling a driver or passenger 290 to provideinformation, such as a navigation destination, to the autonomous drivingcomputer 110.

The autonomous driving computing system may capable of communicatingwith various components of the vehicle. For example, returning to FIG. 1, computer 110 may be in communication with the vehicle's centralprocessor 160 and may send and receive information from the varioussystems of vehicle 101, for example the braking 180, acceleration 182,signaling 184, and navigation 186 systems in order to control themovement, speed, etc. of vehicle 101. In addition, when engaged,computer 110 may control some or all of these functions of vehicle 101and thus be fully or merely partially autonomous. It will be understoodthat although various systems and computer 110 are shown within vehicle101, these elements may be external to vehicle 101 or physicallyseparated by large distances.

The vehicle may also include a geographic position component 144 incommunication with computer 110 for determining the geographic locationof the device. For example, the position component may include a GPSreceiver to determine the device's latitude, longitude and/or altitudeposition. Other location systems such as laser-based localizationsystems, inertial-aided GPS, or camera-based localization may also beused to identify the location of the vehicle. The location of thevehicle may include an absolute geographical location, such as latitude,longitude, and altitude as well as relative location information, suchas location relative to other cars immediately around it which can oftenbe determined with less noise that absolute geographical location.

The vehicle may also include other devices in communication withcomputer 110, such as an accelerometer, gyroscope or anotherdirection/speed detection device 146 to determine the direction andspeed of the vehicle or changes thereto. By way of example only,acceleration device 146 may determine its pitch, yaw or roll (or changesthereto) relative to the direction of gravity or a plane perpendicularthereto. The device may also track increases or decreases in speed andthe direction of such changes. The device's provision of location andorientation data as set forth herein may be provided automatically tothe user, computer 110, other computers and combinations of theforegoing.

The computer 110 may control the direction and speed of the vehicle bycontrolling various components. By way of example, if the vehicle isoperating in a completely autonomous mode, computer 110 may cause thevehicle to accelerate (e.g., by increasing fuel or other energy providedto the engine), decelerate (e.g., by decreasing the fuel supplied to theengine or by applying brakes) and change direction (e.g., by turning thefront two wheels).

The vehicle may also include components for detecting objects externalto the vehicle such as other vehicles, obstacles in the roadway, trafficsignals, signs, trees, etc. The detection system may include lasers,sonar, radar, cameras or any other detection devices which record datawhich may be processed by computer 110. For example, if the vehicle is asmall passenger vehicle, the car may include a laser mounted on the roofor other convenient location.

As shown in FIG. 3 , small passenger vehicle 301 may include lasers 310and 311, mounted on the front and top of the vehicle, respectively.Laser 310 may have a range of approximately 150 meters, a thirty degreevertical field of view, and approximately a thirty degree horizontalfield of view. Laser 311 may have a range of approximately 50-80 meters,a thirty degree vertical field of view, and a 360 degree horizontalfield of view. The lasers may provide the vehicle with range andintensity information which the computer may use to identify thelocation and distance of various objects. In one aspect, the lasers maymeasure the distance between the vehicle and the object surfaces facingthe vehicle by spinning on its axis and changing its pitch.

The vehicle may also include various radar detection units, such asthose used for adaptive cruise control systems. The radar detectionunits may be located on the front and back of the car as well as oneither side of the front bumper. As shown in the example of FIG. 3 ,vehicle 301 includes radar detection units 320-323 located on the side(only one side being shown), front and rear of the vehicle. Each ofthese radar detection units may have a range of approximately 200 metersfor an approximately 18 degree field of view as well as a range ofapproximately 60 meters for an approximately 56 degree field of view.

In another example, a variety of cameras may be mounted on the vehicle.The cameras may be mounted at predetermined distances so that theparallax from the images of 2 or more cameras may be used to compute thedistance to various objects. As shown in FIG. 3 , vehicle 301 mayinclude 2 cameras 330-331 mounted under a windshield 340 near the rearview mirror (not shown). Camera 330 may include a range of approximately200 meters and an approximately 30 degree horizontal field of view,while camera 331 may include a range of approximately 100 meters and anapproximately 60 degree horizontal field of view.

Each sensor may be associated with a particular sensor field in whichthe sensor may be used to detect objects. FIG. 4A is a top-down view ofthe approximate sensor fields of the various sensors. Although thesefields are shown in two dimensions (2D) in FIGS. 4A-4D, the actualsensor fields will be in three dimensions. FIG. 4B depicts theapproximate 2D sensor fields 410 and 411 for lasers 310 and 311,respectively based on the fields of view for these sensors. For example,2D sensor field 410 includes an approximately 30 degree horizontal fieldof view for approximately 150 meters, and sensor field 411 includes a360 degree horizontal field of view for approximately 80 meters. Thevertical field of view is not shown as these are only 2D examples.

FIG. 4C depicts the approximate 2D sensor fields 420A-423B and for eachof radar detection units 320-323, respectively, based on the fields ofview for these sensors. For example, radar detection unit 320 includessensor fields 420A and 420B. Sensor field 420A includes an approximately18 degree horizontal field of view for approximately 200 meters, andsensor field 420B includes an approximately 56 degree horizontal fieldof view for approximately 80 meters. Similarly, radar detection units321-323 include sensor fields 421A-423A and 421B-423B. Sensor fields421A-423A include an approximately 18 degree horizontal field of viewfor approximately 200 meters, and sensor fields 421B-423B include anapproximately 56 degree horizontal field of view for approximately 80meters. Sensor fields 421A and 422A extend passed the edge of FIGS. 4Aand 4C. Again, the vertical field of view is not shown as these are only2D examples.

FIG. 4D depicts the approximate 2D sensor fields 430-431 cameras330-331, respectively, based on the fields of view for these sensors.For example, sensor field 430 of camera 330 includes a field of view ofapproximately 30 degrees for approximately 200 meters, and sensor field431 of camera 430 includes a field of view of approximately 60 degreesfor approximately 100 meters. Again, the vertical field of view is notshown as these are only 2D examples.

The aforementioned sensors may allow the vehicle to evaluate andpotentially respond to its environment in order to maximize safety forpassengers as well as objects or people in the environment. The vehicletypes, number and type of sensors, the sensor locations, the sensorfields of view, and the sensors' (2D or 3D) sensor fields are merelyexemplary. Various other configurations may also be utilized.

In addition to the sensors described above, the computer may also useinput from other sensors. For example, these other sensors may includetire pressure sensors, engine temperature sensors, brake heat sensors,break pad status sensors, tire tread sensors, fuel sensors, oil leveland quality sensors, air quality sensors (for detecting temperature,humidity, or particulates in the air), etc.

Many of these sensors provide data that is processed by the computer inreal-time, that is, the sensors may continuously update their output toreflect the environment being sensed at or over a range of time, andcontinuously or as-demanded provide that updated output to the computerso that the computer can determine whether the vehicle's then-currentdirection or speed should be modified in response to the sensedenvironment.

In addition to processing data provided by the various sensors, thecomputer may rely on environmental data that was obtained at a previouspoint in time and is expected to persist regardless of the vehicle'spresence in the environment. For example, returning to FIG. 1 , data 134may include detailed map information 136, e.g., highly detailed mapsidentifying the shape and elevation of roadways, lane lines,intersections, crosswalks, speed limits, traffic signals, buildings,signs, real time traffic information, vegetation, or other such objectsand information. For example, the map information may include explicitspeed limit information associated with various roadway segments. Thespeed limit data may be entered manually or scanned from previouslytaken images of a speed limit sign using, for example, optical-characterrecognition.

The map information may include three-dimensional terrain mapsincorporating one or more of objects listed above. For example, thevehicle may determine that another car is expected to turn based onreal-time data (e.g., using its sensors to determine the current GPSposition of another car) and other data (e.g., comparing the GPSposition with previously-stored lane-specific map data to determinewhether the other car is within a turn lane).

FIG. 5 is an example of map information 500 for a portion of a roadwayincluding an intersection 510. In this example, intersection 510 is afour-way stop, though map information 136 may include any number ofdifferent roadway arrangements, combinations, and/or features as notedabove. The map information includes lanes 520-527 defined by lane lines530-533 and 540-547. The map information may also include detailsregarding the shape and location of cross walks 550-553. Beyond thebounds of the roadway, the map information 500 may also include featuressuch as sidewalks 560-563, structures 570-573, and vegetation (such astrees) 580-582. Structures 570-573 may include various types ofstructures. For example, structures 570 and 571 may include buildingssuch as a garage, shop, home, office, etc. In another example, structure572 may include a wall feature.

Again, although the detailed map information 136 is depicted herein asan image-based map, the map information need not be entirely image based(for example, raster). For example, the map information may include oneor more roadgraphs or graph networks of information such as roads,lanes, intersections, and the connections between these features. Eachfeature may be stored as graph data and may be associated withinformation such as a geographic location and whether or not it islinked to other related features. For example, a stop sign may be linkedto a road and an intersection. In some examples, the associated data mayinclude grid-based indices of a roadgraph to allow for efficient lookupof certain roadgraph features.

The detailed map information may also be encoded with informationregarding the probability of detecting objects in various areas. Mapinformation 600 of FIG. 600 is an example of such map information. Forexample, instead of the vehicle's sensors having to see wall 572 and thevehicle's computer recognize this feature as a “wall,” the map may notethat wall 572 is opaque to the laser or radar, and thus, the mapinformation 600 may include an area 610 associated with an annotationindicating that the probability of detecting something behind the wall572 (or on the opposite side of the wall as the vehicle's sensors) iszero.

In another example, the map information 600 may indicate that wall 572is 3 feet high. In this regard, the annotation for area 610 may notethat for that area, there is a higher confidence of seeing an objecttaller than three feet and a lower confidence of seeing an object whichis shorter than three feet. In this regard, objects defined in thedetailed map information such as vegetation, buildings, walls,monuments, signs, towers, and other structures or objects may each beassociated with a probability of the vehicle being able to detectanother object of a particular size or shape on the opposite side ofthat structure as the vehicle's sensors.

Computer 110 may also receive or transfer information to and from othercomputers. For example, the map information stored by computer 110 (suchas the examples shown in FIGS. 5 and 6 ) may be received or transferredfrom other computers and/or the sensor data collected from the sensorsof vehicle 101 may be transferred to another computer for processing asdescribed herein. As shown in FIGS. 7A and 7B, data from computer 110may be transmitted via a network to computer 720 for further processing.The network, and intervening nodes, may comprise various configurationsand protocols including the Internet, World Wide Web, intranets, virtualprivate networks, wide area networks, local networks, private networksusing communication protocols proprietary to one or more companies,Ethernet, WiFi and HTTP, and various combinations of the foregoing. Suchcommunication may be facilitated by any device capable of transmittingdata to and from other computers, such as modems and wirelessinterfaces. In another example, data may be transferred by storing it onmemory which may be accessed by or connected to computers 110 and 720.

In one example, computer 720 may comprise a server having a plurality ofcomputers, e.g., a load balanced server farm, that exchange informationwith different nodes of a network for the purpose of receiving,processing and transmitting the data from computer 110. The server maybe configured similarly to the computer 110, with a processor 730,memory 740, instructions 750, and data 760.

In one example, data 760 of server 720 may include provide weatherrelated information. For example, server 720 may receive, monitor,store, update, and transmit various information related to weather. Thisinformation may include, for example, precipitation, cloud, and/ortemperature information in the form of reports, radar information,forecasts, etc.

In addition to the operations described above and illustrated in thefigures, various operations will now be described. It should beunderstood that the following operations do not have to be performed inthe precise order described below. Rather, various steps can be handledin a different order or simultaneously, and steps may also be added oromitted.

In order to determine the vehicle's sensor limitations and adjust thevehicle's behavior, the computer 110 may generate a 3D model how each ofthe vehicle's different sensors are currently able to see observing thevehicle's environment. This may include, for example, what areas thesensors are able to see if the sensor's field of view were completelyunobstructed by objects, rather than what objects and features thesensors are currently seeing. These models may be based on eachindividual sensor's field of view given that sensor's location andorientation relative the vehicle. This information may bepre-determined, for example using a general calibration step, beforedetermining each of the individual sensor models.

For example, FIGS. 8A and 8B include the components of an individual 3Dmodel 800 for sensor 311. The model 800 for laser 311 may include thedimensions of 2D sensor field 411 shown in FIG. 8A (same as FIG. 4B) aswell as a third, vertical dimension 811 shown in FIG. 8B. Thus, acombination of these components (411 and 811) may be used to generate a3D model 800 for laser 311. Similar models may therefore also begenerated for each of the sensors of the object detection component 148.

In addition, the individual sensor models may include probabilistic datawhich describes the confidence of detecting objects at various points orareas within a given sensor field. For example, a particular model mayinclude information indicating the confidence of detecting objectswithin a given sensor field. For example, one model may have a higherconfidence of detecting objects in the middle of a sensor field orwithin some distance of the sensor and a lower confidence at the outeredges of that sensor field.

FIGS. 9A and 9B are examples of the components of a 3D model 900 forlaser 311 having probabilistic data. The shading of the components ofthe 3D model 900 is shown as darker at areas closer to laser 311 wherethe confidence of detecting an object is likely to be higher and lighterat areas further from laser 311 where the confidence of detecting anobject is likely to be lower.

In another example, the models with probabilistic data may include verydetailed information about the size and shape of objects that are likelyto be detected at particular locations within the models. For example,the probabilistic data may describe an area where the sensor is 60%likely to see another vehicle, 20% to see a small non-metallic object,etc.

This initial modeling of individual sensors may also include leveraginginformation about the current state of the weather and adjusting theshape and or probability information for each individual sensor model inreal time. For example, weather may be detected automatically, based ondata received from the sensors for that particular model or a differentsensor, and/or from real time information received from a centrallocation such as server 520. In this regard, computer 110 may receiveweather information, either from the sensors or a central location, anduse this information to adjust the shape or other characteristics of the3D models for each of the sensors. For example, a laser may be lessreliable as a sensor if there is a significant amount of sun glare orprecipitation. Similarly, radar units may be less reliable when used infoggy conditions, etc. Thus, an example approach would be to buildparameterized models of the relevant weather conditions (e.g., fogdensity, rain intensity, ground wetness & reflectivity, sun intensityand direction, etc). Additionally, one may, a priori, construct a modelof how such weather conditions affect the different sensors (e.g.,reduction in effective laser range as a function of fog density, blindspots in the laser as a function of Sun intensity and direction, etc),and apply these adapted models for computing the online field of view ofthe sensors.

Next, the individual models of all the sensors may be aggregated tocompute a comprehensive three-dimensional (3D) model of what areas thesensors are currently able to observe. This comprehensive model may be abinary map simply indicating areas where the vehicle can detect objectsversus areas where the vehicle's sensors cannot detect objects. Thisinformation may already include the weather information incorporatedinto the individual models.

For example, FIG. 10 is an example of an aggregation of 2D sensor fieldsof the various sensors of object detection component 148. Again,although FIG. 10 is shown in 2D, the actual combined model may be in 3D.In this example, objects located within area 1010 (relative to thelocation of vehicle 301) may be detected by the vehicle's sensors whileobjects located outside of area 1010 cannot be detected.

If the individual models include probability data, the comprehensive 3Dmodel may also include probability data. In this regard, the combinedmodel can combine the probability of detection from the individualsensor models in various ways. In one example, the probability for eacharea of the 3D model may be the greatest probability of detection asdetermined by processing each probabilities of each of the individualsensor models. Thus, if one sensor model has a probability of 10%detection of an object the size of a small passenger car in location 1and another sensor model has a probability of 20% detection of an objectthe size of a small passenger car in location 1, the probability ofdetection of an object the size of a small passenger car for location 1may be 20%.

In another example, the probabilities may be combined in more complexways, such as by having confidence regions or thresholds. FIG. 11 isanother example of a comprehensive 3D model 1100 based on a plurality ofmodels for individuals sensors. In this example, each of the individualmodels may already include weather information. Comprehensive 3D model1100 also includes 3 confidence regions, 1110, 1120, and 1130. Asindicated by the shading, region 1110 may have a higher confidence ofdetecting objects (for example greater than 70%) and features in thevehicle's environment than region 1120 (between 40 and 69%). Similarly,region 1120 may have a confidence of detecting objects and features thanregion 1130 (between 0 and 39%). Other comprehensive 3D models mayinclude significantly more or less confidence regions, different typesof confidence values, etc.

This combined model for a plurality of sensors may also be combined withthe detailed map information 136 to compute sensor occlusions and blindspots. As noted above, the detailed map information 136 may be encodedwith the probability of detecting objects. For example, using thecurrent location of the vehicle, as determined from the vehicle'sgeographic position component, the computer 110 may identify a relevantportion of the detailed map information 136 and combine this informationwith the combined model. In this regard, the feature of the detailed mapinformation 136, including the probability of detecting objects, may beused to adjust the combined model. The result of this combination oradjustment may be a model of the vehicle's environment annotated withinformation describing whether various portions of the environment areoccupied, unoccupied, or unobserved (cannot be detected by the sensors).The occupied/free data might come from a combination of real-time sensordata (e.g., model the sensor occlusions from a truck) as well as priordata (e.g., a building near an intersection would block all sensors;tall grass & trees might interfere with lasers & cameras and perhapspartially block radar; a bridge or tunnel with metallic beams mightinterfere with radar, leading to areas with high noise levels, whichwould be equivalent to blind spots). These annotations may also includeprobability data as described above.

FIG. 12 is an example of a combination of map information 600 andcomprehensive 3D model 1100. In this example, wall 572 occludes aportion of the 3D model 1100 as indicated by area 610. Thus,comprehensive 3D model is reconfigured with new confidence regions 1210,1220, and 1230 corresponding to the confidence values of confidenceregions 1100, 1120, and 1130, respectively.

Thus, the computer 110 does not have to reconstruct the geometry of theenvironment based on sensor data, as the vehicle's computer already hasan expectation of what should and shouldn't be seen in the environment.Another advantage of using a prior map is that the system can reasonabout blind spots and occlusions at longer range (before the relevantobjects come into sensing range), e.g., the system might know it isapproaching a blind intersection significantly earlier than the onboardsensors are able to see the objects responsible for the occlusions,which means the vehicle can modify its behavior (e.g., start to slowdown) earlier and drive smoother and safer.

The combined model and map may be used by the computer 110 to makedriving decisions thereby improving safety. For example, the computermay cause the vehicle to slow down if its sensing range is diminished(e.g., driving in fog), reposition the vehicle to get a better view ofthe world, avoid certain types of risky maneuvers (e.g., passing usingthe oncoming-traffic lanes) if the computer not confident enough thatthe sensors are detecting enough of the environment.

Flow diagram 1300 of FIG. 13 is an example of some of the aspectsdescribed above which may be performed by computer 110. In this example,for each of a plurality of sensors of the object detection component,computer 110 generates an individual 3D model of that sensor's field ofview at block 1302. Weather information is received at block 1304, forexample from the sensors or from an external source, such as computer520. The weather information may include, for example, precipitation,cloud, fog density, rain intensity, ground wetness and reflectivity, sunintensity and direction and/or temperature information. Such weatherinformation may be the form of reports, radar information, forecasts,real-time measurements, etc. The computer then adjusts one or morecharacteristics of the 3D models based on the received weatherinformation at block 1306. This accounts for an impact of the actual orexpected weather conditions on one or more of the sensors. After thisadjusting, the computer aggregates the 3D models into a comprehensive 3Dmodel at block 1308. The comprehensive 3D model is then combined withdetailed map information at block 1310. As noted above, this may includedetermining a current location of the vehicle and using this informationto select a relevant portion of the detailed map information to becombined with the comprehensive 3D model. The computer then computes amodel of the vehicle's environment based on the combined comprehensive3D model and detailed map information at block 1312. This model of thevehicle's environment is then used to maneuver the vehicle at block1314.

As these and other variations and combinations of the features discussedabove can be utilized without departing from the subject matter asdefined by the claims, the foregoing description of exemplaryembodiments should be taken by way of illustration rather than by way oflimitation of the subject matter as defined by the claims. It will alsobe understood that the provision of the examples described herein (aswell as clauses phrased as “such as,” “e.g.”, “including” and the like)should not be interpreted as limiting the claimed subject matter to thespecific examples; rather, the examples are intended to illustrate onlysome of many possible aspects.

We claim:
 1. A method comprising: receiving, by a computing system in a vehicle, information concerning a weather condition, wherein the computing system is configured to operate the vehicle based on data from at least one sensor coupled to the vehicle; determining, by the computing system in the vehicle, an impact of the weather condition on the at least one sensor; determining, by the computing system in the vehicle, a driving decision based on at least the impact of the weather condition on the at least one sensor; and operating, by the computing system in the vehicle, the vehicle to carry out the determined driving decision.
 2. The method of claim 1, wherein the weather condition is an actual weather condition.
 3. The method of claim 1, wherein the weather condition is an expected weather condition.
 4. The method of claim 1, wherein the weather condition comprises at least one of a fog density, a rain intensity, a ground wetness, a sun intensity, or a sun direction.
 5. The method of claim 1, wherein the at least one sensor comprises at least one of a camera, a radar unit, or a laser.
 6. The method of claim 1, wherein determining the impact of the weather condition on the at least one sensor comprises: obtaining a model of the at least one sensor's field of view, wherein the model is capable of being adjusted based on the weather condition.
 7. The method of claim 1, wherein determining the impact of the weather condition on the at least one sensor comprises determining an impact of the weather condition on a range of the at least one sensor.
 8. The method of claim 1, wherein operating, by the computing system in the vehicle, the vehicle to carry out the determined driving decision comprises: operating, by the computing system in the vehicle, the vehicle to slow down.
 9. The method of claim 1, wherein operating, by the computing system in the vehicle, the vehicle to carry out the determined driving decision comprises: operating, by the computing system in the vehicle, the vehicle to a position that improves a view of the at least one sensor.
 10. The method of claim 1, wherein operating, by the computing system in the vehicle, the vehicle to carry out the determined driving decision comprises: operating, by the computing system in the vehicle, the vehicle to avoid a certain type of maneuver.
 11. A system comprising: at least one sensor coupled to a vehicle; at least one processor; at least one memory; instructions stored in the at least one memory and executable by the at least one processor to perform operations comprising: receiving information concerning a weather condition; determining an impact of the weather condition on the at least one sensor; determining a driving decision based on at least the impact of the weather condition on the at least one sensor; and operating the vehicle to carry out the determined driving decision.
 12. The system of claim 11, wherein the weather condition is an actual weather condition.
 13. The system of claim 11, wherein the weather condition is an expected weather condition.
 14. The system of claim 11, wherein the weather condition comprises at least one of a fog density, a rain intensity, a ground wetness, a sun intensity, or a sun direction.
 15. The system of claim 11, wherein the at least one sensor comprises at least one of a camera, a radar unit, or a laser.
 16. The system of claim 11, wherein determining the impact of the weather condition on the at least one sensor comprises: obtaining a model of the at least one sensor's field of view, wherein the model is capable of being adjusted based on the weather condition.
 17. The system of claim 11, wherein determining the impact of the weather condition on the at least one sensor comprises determining an impact of the weather condition on a range of the at least one sensor.
 18. The system of claim 11, wherein operating the vehicle to carry out the determined driving decision comprises operating the vehicle to slow down.
 19. The system of claim 11, wherein operating the vehicle to carry out the determined driving decision comprises operating the vehicle to a position that improves a view of the at least one sensor.
 20. The system of claim 11, wherein operating the vehicle to carry out the determined driving decision comprises operating the vehicle to avoid a certain type of maneuver. 